This work consideres asynchronous shared memory systems in which any number of processes may crash. It identifies relaxations of fetch & increment, queues, sets and stacks that can be non-blocking or wait-free implemented using only Read/Write operations, without Read-After-Write synchronization patterns. Set-linearizability, a generalization of linearizability designed to specify concurrent behaviors, is used to formally express these relaxations and precisely identify the subset of executions which preserve the original sequential behavior. The specifications allow for an item to be returned more than once by different operations, but only in case of concurrency; we call such a relaxation multiplicity. Hence, these definitions give rise to new notions and new objects where concurrency explicitly appears in the specification of the objects. As far as we know, this work is the first to provide relaxations of objects with consensus number two which can be implemented using only Read/Write registers.

这项工作考虑了异步共享内存系统，其中任意数量的进程都可能崩溃。它确定了提取和增量、队列、集合和堆栈的放宽，这些可以是非阻塞或无等待的，仅使用读/写操作实现，没有写后读同步模式。集合线性化是线性化的概括，旨在指定并发行为，用于正式表达这些松弛并精确识别保留原始顺序行为的执行子集。规范允许不同操作多次返回一个项目，但仅限于并发情况；我们称这样的松弛多重性. 因此，这些定义产生了新概念和新对象，其中并发性明确出现在对象的规范中。据我们所知，这项工作是第一个提供第二个共识的对象放宽，可以仅使用读/写寄存器来实现。